In my office I have two machines connected two networks - one has IP say 21..... and another has IP say 25... Now the thing is that both of the machines can access Internet. But there is a problem pinging among each other. I have been told that has been done on purpose. I am not sure what is going on here. If there is no private VLAN issues there and if each machine has an IP address then why would not they be able to ping each other. Well this is not an issue here, I need to understand the mechanism here.